Wireless-telegraph system.



O. R. UNDERHILL. WIRELESS TELEGRAPH SYSTEM.

APPLICATION FILED AUG. 10, 1904.

Patent d July 2?, 1909.

M v v I jizvgzz'tork Teen it. concern:

v a i'citizen of the Unrrnn srairns PATENT- orrion.

CHARLES R. UNnE'anrtL, or raovinnncn',

, gnaw JERSEY.

winnm'ss-rnnneanrn SYSTEM.-

Specification-of Letters Patent.

JERSEY, A conrona'rion or i ucaaan filed August 10, 1904. semruo. 220,214.

, 1-138 a knownthatl', omms n, UNDE'RHILL, United States, and a-resident -1'ofQB-rov-idence, in the county of Providence mg a local circuit or clrcuits lIl'WlllCll is incertain new and and State of Rhode Island, have invented useful Improvements in Wireless-Telegraph Systems, of which the following is a specification.

This invention relates to a wireless .tele.

graph system, and especially to a receiving apparatus therefor. of the' -type in which relay'controlled by a coherer or similar device responsive to electrical impulses, disturbances or vibrations transmitted through anatural medium, is employed forv govern- 'cluded the principal remaining electrical element or elements of the receiving apparatus. The principal object of this invention is to provide a wireless receiving apparatus inwhich all the devices controlled by a high-- resistance relay or equivalent device influenced by electrical impulses, disturbances or vibrations transmitted through space may be of simpler and cheaper construction, less sen-' sitive and more eflicient, than the correspondcell of battery and to connect in this circuit ing electrical devices purpose.

heretofore used for the It is well known that in wireless telegraph receiving apparatus the current which passes or other similar device responsive to impulses through the coherer,

transmitted .through space, and through the local circuit controlled immediately thereby, should be of extremely low amperage tate decohering, by mechanical or other means. This currentshould also be of low potential current through the coherer when no signal is being sent, and for the further purpose'of preventing sparking between the particles constituting the circuitmaking-andsbreaking element of the coherer or similar responsive device. For the purpose of properly reducing the voltage and amperage of thecurrent flowing through the coherer it is customary to employ in the local circuit of the coherer a source of energy in the form of a single an exceedingly sensitive relay having a very a fine wire winding. of this sensitive re.- y, poor contact, and therefore oppose-a considerable resistance tothe passage of current,

at the contacts and cause sp resistance of in order to faciliin order to prevent the passage of disadvantages which sary the localcircuit controlled by such rela'y and 'toemploy, a sourc'e-of energy having a corfinanc d-M1 737, 1909.

g p enonn ISLAND, AssroNon TOUNDERHILL TELE- onnrnj fraANs aToa COMPANY, OFJERSEY orrY, NEW

this resistance being due directly to the poorcontact made. With sucha relay it is necesto use high resistance instruments in 4 respondingly 'high potential "in" order to transmitthe necessary power to operate the devices or instruments insuch local circuit. The high resistance instruments which are ordinarily connected in such localcircuit are an electromagnetic decohering device ortapv per and a sounder or recording instrument. The windings of the electromagnets of these devices are of high resistance and the contact points thereof must be protected by shunts of very high resistance,

bear a certain relation to the resistance of.

as the shunt resistance for protecting such contacts must the electromagnet winding inthe c1rcuitogt,.,f

the contacts to be protected. Not only are these high resistances necessaryuw-hen' the local circuit has high includes .directlythe decohering device and other electrical apparatus, sary to employ-a source of energy of relatively high voltage in order to operate such electrical devices successfully. As the resistbut it is also necesresistance contacts and ance of such a circuit is high and'the Volta e 40f the current flowing therein is also hig the tendency of the current to jumpacross arking is conand this tendency increases as the the circuit and ot the shunt around the contact increases. If this shunt resistance be decreased it will be much more 'difiicult to keep the instruments in the local circuit properly adjusted, andf-in this manner their sensitiveness ,is also increased. have found that all sideralole,

are 1 herent in a wireless receiving apparatus having :high resistof these difiiculties and; i

ance contacts and windings may be overcome and obviatedby employing a second local circuit governed bythat local clrcult which ordinarily includes the decoherlng device and sounder or recorder but which in my systemincludes only means for mak ng firm contacts at low resistance contact points of the second local circuit, which in this system controls the decohering device, etc., and.

makes it possible to use low resistancewmd ings therein.

The drawing accompanying-this spec1fication and forming part of the presentap h5- cation is a diagrammatic vi'ewo'f a wire ess telegraph system embodying mv present im- .15 ordinarily employed, the devices shown including a transmitting key 3 connected in eircuit with a source of energy or battery- 4 and withan induction-coil 5 having the usual vibratory circuit-maker-and-bre'aker 6,

a condenser 7 and the usual spark-gap between the spheres 8. a a a (At the receiving station there is employed a device responsive to such electrical impulses, disturbances or vibrations as are capableof being transmitted through a natural mediun1', the devicev shown being the usual 1 coherer 9 connected with the antenna 2 and with ground and controlling a. :local circuit including a source'of energy, usually a single 3 0 cell 10.-- A high resistance relay is also employed at the receiving station and is so combined with the other elements ofthe receiving apparatus as-to be responsive to the electrical impulses, disturbances or vibrations; received. This relay, which is desig' nated by 11, is preferably connected in the 'well-known manner in a local'circuit which includes thecoherer and'the battery 10. The winding of this relay magnetiscomposed of fine wire in order that it may-operate properly in a circuit traversed by a current' of suchsmall amperage and low voltage as Y thatsupplied by the single cell 10. This relay controls a local circuit, which circuit in this case is normally openand may be closed by means of the-usual relay-switch l2 coacting with a contact 13.- This contact 13 and the cooperatin contact 14 on the switch -12 are always hig -resistance contacts and usuallyare connected in a circuit throughwhich considerable power must be transmitted, owing. to the inclusion therein of the'high-resistance windings of the magnets of the decohering and other devices,'such as 56 ",thesounder, the recorder, etc. In this system,

however, while-13 andl l are high-resistance contacts, practically no power is'transmitted '-thereth1'0ugh, because the only translating "device in circuit with these contacts is some 6 means for closing. another or second local fcircuit governing a .decohering device, etc.

' The preferred means employed is a relaymagnet 15. connected in circuit with the contacts 13-and-14 and'Wlth a source of'ener 6,5 .16 by suitable conductors, such as 17, 18am isturbances or vibrations ment.

'19. when this relay magnet 15"is the only translating device employed in this circuit it will be seen that the only'function of the high-resistance relay magnet 11 will be to claw the circuit through the battery l6 and the second relay magnet 15 at the points 13'and 14. Because of this the resistance of the Winding of the relay magnet 15 may be relatively low, say about 10- ohms, and a current of low volt-age maybe employed to energize the winding of the second or 'lowresistance, relay magnet 15. Two cells of f battery will ordinarily 'besufiicientat the point 16 to operatethe second relay. The

function of .this second relay is to obtain a stronger energization of the local circuit controlled thereby than it is possible to-make at the terminals of a high-resistance local circuit cont-rolled directly by the relay magnet 11,"and including the magnet-windings of the decohering device,- etc., which is the systemordinarily used. The second local circuit will usually be strongly energized by ineluding therein only low-resistance windings and by firmly and positively closing the circuit thereof by a switch operate by the relay magnet 15. Such a-switch is indicated at 20 and is connected to the armature of the relay magnet 15,'and in this case has thereon two contacts12l and 22, one of which controls-a circuit through ;a decohering de vice, and the other a circuit through a sounder, a recorder, orother translatingdevice. The contacts withwhich21 and 22 cooperate may be of'the type indicated at 23 and2l, said contacts being in the form of spring tongues one of which'is connected by a conductor 25 to a decohering device 26 and the other by'a. conductor 27 wlth a translating'device 28-which may be a sounder,

recorder or other similar electrical instru-' The devices 26 and 28 are in this system connected in parallel branches of the same circuit, a common source of energy therefor being'shown at 29. This source of energy may contain only one or two cells of battery, and ,all of the-devices included in" the circuit-therewith are of low resistance, the magnet windings-of the devices 26 and- '28 being coarse wires'and the conductors 25 and 27 and also the conductors 30, 31 and 32,

which complete the two branches through the source of energy 29, being conductors of large cross section as comparedwith those inythe circuit of the' rnagnet winding 11 of ,the1first-'relay.'

S'nce agood contact for the second local circuit is assured by" the use of the second relay and by the elimination from the circuit" ,of itsmagnet winding 15 of all unnecessary resistances, it will be obvious thatnot only will it. be possible to uselow resistance windings for the. decohering device, etc., and thereby assure a stron andpositive operation of each of these evices, but that only (lawthe second local circuit. low resistances will therefore prevail both Moreover,

low-resistance shunts will be needed across the local contacts of the second relay and at thc'terminals of all the magnet windings in.

Low voltages and for the purpose, and the windings of the electromagnetswill befar more efficient than those employed in a iii 'h resistance circuit, owing to the greater e ciency of the'large sizewires employed,. which makes the ratio of conductor to insulator greater than in the case of high-resistance windings.

What I 'claimfis: v 1. .In a system of wireless telegraphy, the

' combination with an electrical receiving de- -vice responsive to electrical impulses'or disturbances transmitted through a natural medium, of a relay also controlled by saidim pulses or disturbances, a local circuit controlled by said relayand embodying a low-" resistance circuit-controllingwinding, and a second .localcircuit. controlled by said first local circuit and comprising receiving means:

said receiving means including low resistance V circuit controlling contacts and one -or more translating devices with lowresistance winding.

combination with an electrical receiving de- 2. In a system of wireless telegraphy, the

vice responsive to electrical impulses or dist'urba-noes transmitted'through a natural med1um,.of a relay also controlled bysaid im pulses or disturbances, a local circuit con-- trolled by said relay and embodying a lowresistance circuit-controlling winding, and a second local circuit controlled by said first local circuit and comprising receiving means only, said receiving means including means with low resistance winding for governing the operation of said electrical receiving de- 3. In a system of wirelesstelegraphy, the combination 1 with an electrical receiving device responsive to electrical impulses or disturbances transmitted throu h,'a' natural 'med'ium, of a relay also oontr'oIld byfsaid impulses or disturbances, av local circuit controlled by; said relay and embodying a low resistance circuit-controlling winding, and a second local circuit controlled. by said first local circuit and comprising receiving, means only, said. receiving means-including one or more controlling devices and all the elements -of. said circuit being "of relatively low re sistance as com'p'aredwith the resistance of .said relay.

4. In a system or wireless telegraphy, the combination with -colierer. {v

of wireless telegraphy, the

viceresponsive tolelectrial impulses or disturbances transmitted-througl1.' a natural medium, of a' relay also. controlledbysaid im-= a coherer responsive to;

pence-ml impulses or disturbances trans- 4 of a relay *also controlled by said impulses or disturbances, a localcircuit controllediby said relayand"embodyingv a low-resistance circ'uit-conmitted through .a natural medium,

trolling winding, and a second local circuit controlled by saldfirst local circuit and comprising receiving. means only, said receiving oneor more translating de means including 'vices'wlthlow resistance'wlnding.

5. In a system.of'wireless telegraphy, the combination with a coherer responsive to electrical. impulses; or disturbances transmitted through. a natural'med-ium, of a relay also controlled, by said impulses or-disturband embodying a low-resistance circuit-controlling-windin and a second'local circuit controlled said firstlocal. circuit and comprising receivingmeans only, said receiving means including adecohering' tapper with;

ances, a local circuit controlled by'said relay I low resistance winding cooperating with said 6. Ina'system combmat1on;w1th an electrical recelvlng depulses or disturbances, a local circuit controlled by said relay andembodying a low-- resistance circuit controllin'g winding, and a second. local circuit controlled by said first local circuit and compr sing receiving means only, said receiving means including. a.de

cohering tapper cocperative with said-c0 hrer and all the elements of said circuit being of relatively low resistance as compared with the resistance of said relay.

7. In a systemIof wireless 'telegraphy, the

'combination with an electrical receiving de- .-v1ce responsive to electrical impulses or dis turbances transmitted through'a natural medium, of a relay also controlled by said im-;.

.pulses or disturbances, a local circuit controlled by said relay and embodying a 'lowresistance circuit-controlling winding, and a corder and all :the elements of said circuit being of relatively low resistance as compared with the resistance of said relay.

8. In a system of wireless telegraphy, the

combination with a coherer respons1ve to electrical impulses or disturbances transmitted througha natural medium, of a relay also controlled by said impulses or disturbances, a local circuit controlled by saidrelay and'embodying a low-resistance circuit-controllin winding, and a second local circuit second local circuit controlled by said first local clrcuit and comprlsmg receiving means only, send receiving means including a recontrol ed by .said first local circuit and s comprising receiving meansonly, said receivlng means including a recorder and'a decohering tapper and. allthe elements -'of* .saidcircu-itbeing of relatively low reslstance as compared with the resistance of said r'elay. a

9. In a system of wireless telegraphy, the combination with-an electrical receiving device responsive to electrical impulses or disturbances transmitted 'thi'ou h a natural medium, of a relay also controlled by said impulses or disturbances, a local circuit conv trolling winding, asecond relay controlled trolledlby said relay and embodying a lowresistance circuit-controlling winding, a second relay controlled by said local circuit, and a second local circuit controlled by said "second; relay and comprising receiving by said local circuit, and a second local circuit controlled by said second relay and comprising receiving means only, said receiving means including a decohering' tapper with low resistance winding cooperative with said coherer.

11. In a system of wireless telegraphy, the

combination with an electrical receiving device responsive to electrical impulses or disturbances transmitted through a natural medium, of a relayalso controlled by said impulses or disturbances, a local circuit controlled by said relay and embodying a lowresistance circuit-controlling winding, a sec- 0nd relay controlled by said local circuit, and a second local circuit controlled by said second relay and comprising receiving means only, said receiving means including a recorder.

12. 'In a system of wireless telegraphy, the combination witha coherer responsive to electrical impulses or disturbances transmitted through 'a natural medium, of a relay also controlled-by said impulses or disturb-- ances, a local circuit controlled by said relay and embodying a low-resistance circuit-controlling winding, a second relay controlled by said local circuit, and a secondlocal circuit centrolled by said second relay and comprising receiving means only, said receiving means including a decoherlng tapper with low resistance winding cooperative with said coherer and-a recorder I Signed at New York "in the county of New York, and State of llew York,this 8th day of August A.-D. 1904. v

CHARLES R. UNDERHILL. Witnesses v(3. 'S. CH MPION,

Rt QHAMiION. 

